Control mechanism for circular knitting machines



Oct. 3, 1933. G. NOBST ET AL 1,929,075

CONTROL MECHANISM FUR CIRCULAR KNITTING MACHINES Filed Jan. 2a, 1928 55 p 2 5 B grim- G v r .12 d I c/nvenz ons;

2 ra 4% A 5 M J i r Patented Oct. 3, 1933 UNITED STATES PATENT OFFICE CONTROL DIECHANISM FOR CIRCULAR KNITTING MACHINES Application January 26, 1928, Serial No. 249,630, and in Germany January 27, 1927 20 Claims.

The present invention relates to an improvement in control mechanism for circular knitting machines. The improvements hereinafter to be described are more particularly adapted for use in circular purl knitting machines such for instance as the type illustrated in our pending application for United States Patent Serial No. 223,l35, filed September 15, 1927 [Patent No; 1,720,606, dated July 9. 1929], either with or without jacquard mechanism such as described and shown in our application for United States patent executed of even date herewith for Pattern'forming mechanism forcircular knitting machines, Serial No. 249 ,29-, illed'January 26, 1928 [patented April mll932, No. 1,852,256l-or other appropriate iacquard mechanism.

One object of, the invention is to secure wider diversity of pattern than has previously been possible in tubular goods knitted on circular purl knitting machines. For this purpose we employ one or more pattern wheels in conjunction with the cam cylinder of a circular purl knitting machine and produce patterns including tuck, purl and rib stitches with a wide range of combinations of all three, if desired.

One embodiment of our invention is illustrated in the drawing accompanying the present speciiication and in which Fig. 1 is a development of a cam cylinder adapted to be used in conjunction with needle cylinders of a purl knitting machine;

Fig. 2 is a fragmentary transverse horizontal section on an enlarged scale on the line 2-2 of Figure 1;

Fig. 3 is a fragmentary vertical section on the line 3-3 of Figure 1, showing the selector wheel;

Fig.4isaviewsimilartoFigure1andillustrates a modification by means of which it is possble to make patterned purl fabric without the use of a Jacquard:-

Fig. 5 is a view similar to Figure 1 and illustrates a further modification for making patterned p'url fabric;

Fig. 6 is a fragmentary vertical section of part of the needle and cam cylinders of a circular purl knitting machine indicating a connection for a jacquard device; and

Fig. 6 is a composite diagrammatic section through the cam cylinder substantially on the lines AA, 13-8, and D-D respectively of Figs. 1 and5.

The circular purl knitting machine illustrated in the drawing is in general identical with that disclosed in our aforesaid Patent No. 1,720,606,

' to which reference may behad for a full disclosure of suitable means for individually controlling needles, by the use of rocking actuating jacks or sliders, together with appropriate cam devices for rocking the jacks into and out of engagement with their needles. Thus as in the so patented device, the present machine preferably includesa lower needlecylinder r and an upper needle cylinder at superposed thereon and suitable cam cylinders with provision for relative movement of rotation between said needle and cam 5 cylinders, the cam cylinder as shown being the rotary element. Double-ended needles e I are arranged to slide longitudinally in the aligned tricks of said cylinders and their'movement is controlled by means of suitable jacks or sliders each comprising a pusher s and a hook, as f and I, said hooks being provided with butts 50 and 50' respectively. A cam cylinder 40 encircles .the needle cylinders r and u and includes a lower cam 42 positioned and adapted to 15 coact with the hook butts in the lower cylinder 1' and an upper cam 41 positioned and adapted to coact with'hook butts in the upper cylinder u. Thecam cylinder may obviously consist of a single unitary structure or of separate upper 30 and lower members suitably united and when hereinafter reference is made to upper and lower cam cylinders this expression is intended to mean either the upper and lower parts of a single cylinder or separate units constituting the equivg alent of a single cylinder.

In the form of device illlustrated in Fig. 1, the lower cam 42 is provided with separate butt engaging and guiding paths 4'! and 48 which converge adjacent to the working face of a knitting 9o cam 51 and form around the end of said earn a. single path. A switch cam 54 is pivotally mounted in the lower cam 42 in such a position that it may be moved across the entrance to the chan nel 47, conveniently identified as the idle chang nel, to deflect the hook butts 50 into the adjacent opening 53 of the working channel 48. The lower cam 42 is provided with an obliquely disposed opening 46 extending across and communicating with paths 47 and 48. A selector wheel 43 0 is mounted on the lower cam 42 and in such position that the teeth 44 thereof extend through said' opening and engage the lower cylinder r, Figs. 2 and 3. The teeth 44 of wheel 43 are obliquely arranged thereon and form 'spaced notches into which slugs 45 may readily be inserted and removed. In the construction illustrated in Figs. 1 to 3 inclusive. slugs 45 are in-' serted in alternate notches.

Referring to Fig. 6'. the inner faces of the cam rings 1 and 2 which define the grooves 4'7 and 48 and the cam rings 3 and 4 which define the groove 47 are so shaped as to rock the jacks, or at least the retracting portions of the jacks, in and out, toward and from the needle cylinders. Thus throughout the main portion of the circumference of the cam cylinder Fig. 5, Section D) the cam element 1 above the groove 48 and the cam element 3 below the groove 47' have inclined or beveled faces, as also indicated at left side of Fig. 6, which permit the hook ends of the jacks to swing outwardly away from the needle cylinder, At the same portions of the cam cylinder the cam elements 2 and 4 which engage the tails of the jacks are of substantially rectangular cross section in any radial plane, as shown at the left-hand side of Fig. 6 so as positively to maintain the jacks rocked on their pivot points into inoperative position, that is to say, with their hook ends outwardly away from the needles. However, at about the radial plane indicated by the line A--A (Fig. 5) the element 1 in the lower part of the-cam cylinder merges into a portion 1 which is substantially rectangular, while the element 2 merges into a portion 2? which is beveled or inclined. As a jack of the lower series passes the plane A, the cam elements 1 and 2 swing the jack so that its head moves radially inward to a position to engage the hooks of a needle properly positioned to receive it.

On the other hand, the cam element 3 of the upper portion of the cam cylinder at substantially the plane B-B, which is ahead of the plane A-A, merges into a part 3 of rectangular section (Fig. 5, Section BB), while the cam element" 4 at the same plane merges into a part 4* of beveled or inclined section. Thus as the jacks of the upper series pass the plane B-B. their heads or hook portions begin to swing inwardly into a-position to engage the hook of a needle, but since the plane 13-3 is in advance of the plane A-A in the direction of rotation of the cam cylinder, the jacks of the upper series are, under ordinary circumstances, swung into operative position before those of the lower series and thus needles engaged by the upper jacks are moved by the upper jack actuating cam 58 and carried out of the range of the hooks of the lower jacks as the latter are swung inwardly at the plane A--A.

For making a fabric with patterns on the apparatus thus far described, it will be necessary only to selectively employ the jacks or sliders f in the lower cylinder r. Appropriate selection of these jacks is brought about by operation of the selector wheel 43 which, during rotation of the cam cylinder, is itself rotated and operates to select predetermined sliders for effective loop forming action. As indicated in Fig. l, needle or jack butts 50 are shown in normal inoperative position in path 47 to the right or in front of the selector wheel 43, the arrow indicating the direction of movement of the cylinder. As the periphery of said wheel passes over the butts 50, during the rotation of the cylinder, the slugs engage alternate butts and slide them upwardly into the path 48 while the remaining butts or those which havebeen opposite the empty grooves in the wheel 43 remain in the path 47. Those of the butts 50 which have been elevated to path 48 carry their corresponding sliders upwardly and the latter present their entrained corresponding needles in position to receive thread from thread-feeding devices, not shown. Meanwhile the needles controlled by the slider butts remaining in the lower channel 47 do not move up far enough to cast off. However, all of the butts 50 enter the single channel adjacent to knitting cam 51 and encounter the forward face thereof and are depressed thereby into loop forming position. As long as the switch cam 54 remains open, as indicated in Fig. 1, this selecting of alternate jacks for stitch forming operation will continue. If the number of needles is an odd number, different needles will be selected by wheel 43 at successive courses as well understood in the art. Selecting may, however, be stopped without stopping the machine by turning the cam 54 into path closing position so that the butts 50 will then be guided into the path 48, whereupon unpatterned knitting takes place. It will be understood that the bights of yarn laid on the idle needles remain thereon and are knocked over to form tuck stitches when the next stitch is effected.

A circular knitting machine equipped with the modified form of cam cylinder shown in Fig. 4 utilizes the sliders f, s and f, s, respectively, in both the lower and upper cylinders and will therefore produce purl fabric in connection with a variety of patterns by use of the selector \vheel. As shown in said figure, upper cam cylinder 41 is provided with an idler channel at the left of wheel 43, Fig. 4, whereas the lower cam cylinder 42 has only a working channel 48. By this arrangement, the needles actuated by the sliders having their butts engaging channel 48 in the lower cam cylinder all form downwardly drawn loops so long as cam 150 is raised, whereas the needles actuated by the upper cam cylinder may or may not form upwardly drawn loops. A selector wheel 43 having the same construction as selector wheel 43 hereinabove referred to, is positioned to transfer alternate jack butts 50 out of active channel 4'7 into the raised idle position indicated at 50"; their needles are not engaged by a hook I to be moved upwardly by the stitch cam 51', and may knit downwardly at stitch cam 52. The remaining jack butts 50" pass the selector .wheel 43 and are engaged by a cam 58 to rock the hook jack f whereby their hooks are caused to engage the hooks of their respective needles, and the needles knit upwardly at stitch cam 51. Continued rotation of the cam cylinder brings the butts of these slider hooks into engagement with the knitting cam 51 to form upwardly drawn stitches on their corresponding needles. Meanwhile, the slider hooks having butts 50 have not engaged their corresponding needles. having been lifted by wheel 43 too far up to engage the needle hooks, and these needles therefore pass the knitting cam 51' without casting off and thus form tuck stitches, unless their double-ended needles are acted upon to knit downwardly at the cam 52. The needles corresponding to slider butts 50 thus make tuck stitches, unless there are sliders for them in corresponding grooves in the lower cylinder, in which case they knit in the lower cylinder. All of the upper series of slider butts are again returned to the active channel 4'7 and the operation of selection is again repeated, if, desired. It will be ob-' vious that a wide range of groupings of the sliders in the upper cylinder will be possible through the use of the selector wheel 43' and that the various combinations thus afforded may be-still further diversified by the introduction of the rib stitches .formed on needles operated by the cam 52 in respect to the lower cylinder.

The range of pattern variation is still further extended by combining the selector wheel arrangements illustrated in Figures 1 and 4 respectively. Such a modification is shown in Fig. 5. Assuming that the selector wheels 43 and 43' are fitted with slugs in alternate notches as hereinabove described, and that the switch cam 54 occupies the open position shown in Fig. 5, it will be apparent that all of the slider butts 50 operating in path 47 will encounter the selector wheel 43. The butts of sliders designated to form new loops are moved by the pattern wheel 43 into the working path 48 so that, as the knitting cam 51 engages said butts, downwardly-drawn loops are formed on their needles. whereas the jacks which have notbeen engaged by the pattern wheel 43 travel through the idler channel 47 without seizing their needles to work them to form new loops, the loops last formed being retained on the corresponding needles with the new tuck loop, thus producing a pattern. These needles not having been advanced to take the yarn, this is a pattern of missed or draw stitches, the needles retaining the previous loop, and taking no new yarn. In the upper cam 41 the selected slider butts 50' are moved by the selector wheel 43' into the upper idle position 50", and their needles are not moved upwardly to knit. The other sliders at 50" will engage their respective needles after this upward movement when rocked at 58 and are then adapted to drag their needles along during said upward movement to knit, whereas the lower sliders in groove 48 are not adaptedto seize their needles until they are nearer the stitch cam 52. In this respect the arrangement and cooperation of the hook sliders respectively for the upper and lower cylinder, the stitch cams 51' and 52 may be the same as those in our said application Serial No. 223,135, filed September 15, 1927 (Patent No. 1,720,606, dated July 9, 1929), and these devices are therefore not herein claimed, except as elements of the present combination. Thus, although any given lower slider 50 has been previously raised to working position in groove 48, it is incapable of causing its needle to form a stitch unless it is located opposite an upper jack left in position 50', in the channel 47. 'Two different patterns on wheels 43 and 43' may thus periodically repeat their results in the fabric without confusion, the upper cam cylinder being effective'when conflict results from recurrent inconsistent or opposite indications caused by the respective wheels 43 and 45.

As indicated in Fig. 6, the upper end of each hook I is provided with a slot or recess w adapted to receive and retain one end of the harness thread forming part of a jacquard mechanism of any suitable type. The pneumatically operated jacquard mechanism more fully described in our said application Serial No. 249,629, filed January 26, 1928, is referred to for illustrative purposes. A knitting machine combining a suitable jacquard and the selecting mechanism illustrated in connection with the cam cylinder shown in Fig. 4, is capable of producing as widely varied designs as those produced by the cam mechanism shown in Fig. 5. In fact, the range of combinations from the jacquard is greater on account of the flexibility of the jacquard as compared with the selector wheel. Similarly, we contemplate that such a jacquard shall be combined with the cam mechanism shown in Fig. 5. It will be noted that with the use of selector wheels, the pattern figure is repeated periodically. Where a jacquard is used with one or more selector wheels, it is the function of the jacquard to introduce a variety of patterns into those portions of the fabric occurring between the pattern effects produced by the pattern wheels.

In each of the forms of the machine shown in Figs. 1, 4 and 5 we have shown a movable switch cam 150 adapted when moved to lift all of the slider butts 50 of the series of sliders in upper cylinder u to the upper idle position. When cam 150 is so moved, none of the needles in the upper cylinder can be seized by its slider or moved upwardly to knit.

In operation, in the form of this invention shown in Figs. 5 and 6, the selector wheel 43 and its cooperating devices, the switch 54 being in the position shown, selects sliders to enter the groove 48, and leaves sliders in groove 47, according to the pattern set by the slugs inserted in its grooves. Sliders left in groove 47 cause their needles to retain their loops, and these needles mis-stitch, since they are not lifted high enough to be fed. Needles of sliders lifted to groove 48, unless seized and taken to the upper needle cylinder, are fed, and knit at cam 52. Whenever switch 54 is operated, all of the sliders are sent to groove 48, and their needles are normally operated to knit at cam 52, except those needles, if any, seized and taken to the upper needle-cylinder. Whether or not any needle is seized and taken to the upper cylinder is determined by the selection of sliders of the upper cylinder or carrier u by selector wheel 43', which-operateslater than the wheel 43, slugs in it lifting sliders of the upper cylinder too high to seize needles whose sliders are in groove 48 of the lower cam cylinder. Sliders of the upper cylinder not lifted by wheel 43', or by a jacquard connection, if used, seize any corresponding needle whose slider is in groove 48 of the lower cylinder, for example by the operation of wheel 43 or stitch 54, when the slider hooks f are rocked by cam 58, and operate this needle to knit at cam 51. Any needle previously taken to the upper needle cylinder whose slider in the lower needle cylinder is not lifted to groove 48 and whose slider in the upper needle cylinder is lifted by wheel 43' or otherwise, is left in the position of Fig. 6 ready to be again seized whenever either an upper or a lower slider is positioned to seize it, and remains in this position (Fig. 6) until so seized, without casting off the last loop knit upon it.

If all or any part of the needles are in the upper cylinder,lifting their sliders by slugs on selector wheel 43', or by a jacquard connection, leaves the selected needles free to be taken by corresponding lower cylinder sliders whose butts are then in groove 48, as determined either by selector wheel 43, or by switching all of the lower sliders into groove 48 by switch 54. Any needle which has been operated to knit at a previous course, and thereafter left in the position of Fig. 6 to receive yarn on its shank, and then seized to knit in eitherupper or lower cylinder, will have knit a tuck stitch. Any needle operated for a succession of courses in either cylinder will have knit plain fabric. Any series of needles operated at successive courses to knit in one cylinder and then in the other will have made purl fabric. Any alternation of needles or groups of needles knitting in the same course in different cylinders will have knit ribbed fabric. By the device of independently selecting needles to knit or not to knit at the cams respectively for the upper and lower cylinders, and by controlling by one of these selections the seizure of needles to pass from one cylinder to the other, this machine reaches a capacity for varied pattern enabling ornament by plain fabric facing either way, by purling, by ribbing, by mis-stitching in fabric facing one way and by tucking in respect to either face. These effects in the fabric are subject to pattern control and variation by the pattern device 43 for the lower cylinder, the pattern device 43 for the upper cylinder, and, if desired, by the operation of jacquard connections to the sliders of the upper cylinder operating instead of or in addition to the function of the pattern wheel 43'. s

Many modifications which do not depart from the scope of the invention will occur to those skilled in the art.

We claim:

1. In a circular knitting machine having needles and sliders therefor having butts, the com bination of cam means having a knitting cam and separate paths respectively to guide the butts of said sliders to cause them to be operatively moved by the knitting cam, or to cause them to pass said knitting cam without causing their needles to be operated to knit thereby, with selector means in advance of the knitting cam for selectively moving said butts from one to the proaching a knitting cam to predetermine action or inaction of a corresponding needle by the effect of said cam.

3. A knitting machine having needle carriers with aligned grooves, double-ended needles and actuating sliders therefor in said grooves, and cam mechanisms, each including a knitting cam for operating sliders in respect to each of said needle carriers, in combination with independently operating selector mechanisms severally cooperating with said cam mechanisms for each of said carriers to select and move a slider approaching a knitting cam to predetermine action or inaction of a corresponding needle by the effect of said cam, one of said selector mechanisms operating in advance of the other.

4. Knitting machine having needle carriers with aligned grooves and slider-actuated doubleended needles capable of knitting in either carrier, cam mechanism including knitting cams for actuating sliders in each of said carriers, sliders in each of said carriers. means for causing sliders to seize needles and actuate them to knit when the sliders approach the knitting cams in certain positions, in combination with selector mechanism acting in advance of said knitting cam and seizing means in respect to one of said carriers for predetermining an idle position for selected sliders, and selector means for the other carrier for predetermining a position for sliders in that carrier to cause needles to be advanced or withdrawn in relation to the place of action of said seizing means in and for the other carrier.

5. Knitting machine having needle carriers with aligned grooves and slider-actuated doubleended needles capable of knitting in either carrier, cam mechanism including knitting cams for actuating sliders in each of said carriers,

sliders in each of said carriers, means for causing sliders to seize needles and actuate them to knit when the sliders approach the knitting cams in certain positions, in combination with selector mechanism acting in advance of said knitting cam and seizing means in respect to one of said carriers for predetermining in idle position for selected sliders, and selector means for the other carrier for predetermining a position for sliders in that carrier to cause needles to be advanced or withdrawn in relation to the place of action of said seizing means in and for the other carrier, and means for delivering sliders which have been positioned for seizing needles to the knitting cam for actuation thereby.

6. A knitting machine having needle carriers with aligned grooves, double-ended needles and actuating sliders therefor in said grooves, and cam mechanisms, each including a knitting cam for operating sliders in respect to each of said needle carriers, in combination with independently operating selector mechanisms severally cooperating with said cam mechanisms for each of said carriers to select and move a slider ap.

proaching a knitting cam to predetermine action or inaction of a corresponding needle by the effect of said cam, one of said selector mechanisms 'comprising jacquard-operated connections for withholding selected sliders from position to seize a needle.

7. In a. circular purl ,knitting machine of the aligned needle-cylinder and double-ended needle type. the combination of sliders for the needles having butts, and knitting cams cooperating with sliders in upper and lower cylinders respectively, of pattern selector means working on the sliders of the upper cylinder to position them to cause their needles to be worked or to be idle in respect to the knitting cam, with pattern selector means working on the sliders of the lower cylinder to .position them to cause their needles to be worked or to be idle in respect to the knitting cam for the lower cylinder.

8. A circular knitting machine having a needle cylinder, double-ended needles slidably arranged therein, sliders for said needles, butts on the sliders, a knitting cam, a cam cylinder having separate butt guiding paths converging to form a single path at said knitting cam. an adjustable switch cam mounted on said cam cylinder and adapted to be interposed at will between said single path and one of said separate paths, and means carried by said cam cylinder for selectively moving said butts from one to the other of said separate paths.

9. In a circular knitting machine the combination of a needlecylinder, double-ended needles slidably arranged therein, sliders consisting of needle engaging hooks having butts and needle engaging pushers cooperating with said hooks, the needles normally being disengaged from the hooks, a cam cylinder having separate butt guidin paths and pattern means carried by said cam cylinder for selectively positioning said butts in one or the other of said paths.

10. In a circular knitting machine the combination of upper and lower needle cylinders, double-ended needles, needle actuating sliders mounted in each needle cylinder, the needles normally being disengaged from the sliders of both cylinders, a cam cylinder having means for actuating the sliders in the upper cylinder and separate means for actuating sliders in the lower cylinder, and selector means cooperating with the slider actuating means and operative to prevent engagement of selected needles by sliders in either cylinder.

11. In a circular knitting machine the combination of upper and lower needle cylinders, double-ended needles and needle actuating sliders mounted in each needle cylinder, the needles normally being disengaged from the sliders of both cylinders, a cam cylinder having means for actuating the sliders in the upper cylinder and Separate means for actuating sliders in the lower cylinder, said latter means including separate slider-butt guiding surfaces, and means mounted upon the cam cylinder and cooperating with the sliders in one of the cylinders and with said separate guiding surfaces selectively to position said sliders with respect to, said guiding surfaces.

12. In a circular purl knitting machine the combination of upper and lower needle cylinders, double-ended needles, needle actuating sliders mounted in each cylinder, the needles normally being disengaged from the sliders of both cylinders, an upper cam cylinder and a lower cam cylindeigone of said cylinders having an idle and an active guiding path for slider butts, and means for selectively moving slider butts fromthe idle path to the active path.

13. In a circular purl knitting machine the combination of upper and lower needle cylinders, double-ended needles, needle actuating sliders mounted in each cylinder, an upper cam cylinder and a lower cam cylinder, each of said cam cylinders having separate guiding paths for slider butts, and means in each cam cylinder for se lectively moving slider butts from one of said paths in said cam cylinder to the other path therein.

14. In a circular purl knitting machine, the combination of upper and lower needle cylinders, double-ended needles, needle actuating sliders, an upper slider actuating cam part and a lower slider actuating cam part, one of said cam parts having separate slider guiding paths, and means interposed in said paths for selectively moving sliders from one of said paths to the other, .and selector mechanism operative upon sliders worked by the other slider actuating part to determine operative or inoperative relation of said slider to the corresponding needle.

15. In a circular purl knitting machine the combination of upper andlower needle cylinders, double-ended needles and needle actuating sliders therein, an upper cam cylinder and a lower cam cylinder, each of said cam cylinders having separate slider guiding paths, means on each cam cylinder for selectively moving sliders from one of said paths in said cam cylinder to the other path therein, and jacquard mechanism operatively connected to the sliders in one of said cam cylinders.

16. In a circular purl knitting machine the combination of upper and lower needle cylinders, double-ended needles and needle actuated sliders therein, an upper cam cylinder and a lower cam 1'7. In a circular purl knitting machine the combination of upper and lower needle cylinders,

double-ended needles and needle actuating slider s therein, an upper cam cylinder and a lower cam cylinder, each of said cylinders having a working path and an idle path, a selector wheel mounted on each of said cam cylinders selectively to engage and move sliders from one of the paths in said cam cylinder to the other path therein, and a switch cam mounted on one of said cam cylinders for moving said sliders out of the idle path therein. I

18. In a knitting machine of the alignedneedle bed, double-ended needle type having needle beds and needles, a stitch cam corresponding to each needle bed, the stitch points of said stitch cams being substantially in alignment, sliders in each bed actuable by the respective stitch cams to impart loop forming movement to the corresponding needles, slider controlling means spaced in advance of each stitch cam and operative to cause sliders approaching such stitch cam to take a needle seizing position, the spacing of the respective slider controlling means from the corresponding stitch cams being different so that one such controlling means always acts before the other, in combination with patterning means associated with one at least of said slider controlling means and operative to move selected sliders interspersed among others out of position to engage their needles before such selected sliders are acted upon by the corresponding slider controlling means.

19. In a knitting machine of the aligned needle bed double-ended needle typehavingneedle beds and needles, a stitch cam corresponding to each needle bed, the stitch points of said stitch cams being substantially in alignment, sliders in each bed actuable by the respective stitch cams to im-v part loop forming movement to the corresponding needles, slider controlling means spaced in advance of each stitch cam and operative to cause sliders approaching such stitch cam to take a needle seizing position, the spacing of the respective slider controlling means from the corresponding stitch cams being different so that one such controlling means always acts before the other, in combination with a rotary selecting device associated with one of said slider controlling means and operative to move selected sliders interspersed among others out. of position to engage their needles before the selected sliders are acted upon by the slider controlling means.

20. In a knitting machine of the aligned needle bed double-ended needle type having needle beds and needles, a stitch cam corresponding to each needle bed, the stitch points of said stitch cams being substantially in alignment, sliders in each bed actuable by the respective stitch cams to impart loop forming movement to the corresponding needles, slider controlling means spaced in advance of each stitch cam and operative to cause sliders approaching such stitch cam to take a needle seizing position, the spacing of the respective slider controlling means from the corresponding stitch cams being different so that one such controlling means always acts before the other, in combination with independent selector devices associated with each of the respective slider controlling means and operative to move selected sliders out of position to engage their needles before such sliders are acted upon by the corresponding slider controlling means.

. I GEORG NOBST.

ERNST ULBRICHT. 

